Trend in Artificial Nanostructures

Abstract

Nanotechnology "nanotech (NT)" is manipulation of matter on an atomic, molecular and supramolecular scale. The earliest, widespread description of NT referred to the particular technological goal of precisely manipulating atoms and molecules for fabrication of macroscale products, also now referred to as molecular NT. This reflects the fact that quantum mechanical effects are important at this quantum realm scale, and so the definition shifted from a particular technological goal to a research, inclusive of all types of research and technologies that deal with the special properties of matter occur below the given size threshold. It is therefore common to see the plural form NTs/nanoscale technologies refer to the broad range of research and applications whose common trait is size. NT covers naturally very broad, including fields of science as diverse as surface science, organic chemistry, molecular biology, semiconductor physics, microfabrication, etc. The associated research and applications are equally diverse, ranging from extensions of conventional device physics to completely new approaches based upon molecular self-assembly, developing new materials with dimensions on the nanoscale to direct control of matter on the atomic scale. Scientists currently debate the future implications of NT. NT may be able to create many new materials and devices with a vast range of applications, such as in medicine, electronics, biomaterials energy production and consumer products. On the other hand, NT raises many of the same issues as any new technology, including concerns about the toxicity and environmental impact of nanomaterials, and their potential effects on global economics, as well as speculation about various doomsday scenarios.

S.K. Lamichhane*, PhD

*S.K. Lamichhane is a Professor of Physics in the Department of Physics at Prithvi Narayan Campus, Pokhara. He has more than two decades of working experience in academia as a science educator and a researcher in various capacities. He has PhD degree in Physics from JN University, India. His research area is in MEMS of Strained Silicon Semiconductor Structure. He has authored dozens of original research and general articles in his field of interest in various national and international journals. He is the author of physics textbooks and reference books. He has served as a chief Executive director in B.P. Koirala Memorial Planetarium, Observatory and Science Museum Development Board. He is also a recipient of Nepal Vidya Bhushan Padak award.

Date: 15 April, 2017 02 Baisakh, 2074

EPISODE - 04

Drug Designing and Solid Supported Microwave Synthesis

Abstract

The efficacy of drugs can be altered by changing certain functionalities in the drug molecules. The guiding principles of drug designing are bio-disposition, toxicity, efficacy, pharmacokinetics, etc. Use of simple and easily available precursors to design valuable drugs is the principle of modern drug designing. Similarly, use of clean energy and green chemicals draws interest of chemists devoted in synthesis. Microwave assisted solid supported synthesis has acquired spirit of green chemistry as it meets the fundamental challenges of protecting human health and the environment. The microwave-coupled solid supported reactions run with atom economy, rate enhancement, high yield, chemical selectivity and environmentally benign principles. Microwave irradiations cause completion of the chemical reactions within seconds instead of hours in conventional reactions. Some of the commonly used inorganic solid supports are alumina, silica, montmorillonite K10 clays, bentonite, zeolite, etc. based on the nature of reactions. Some novel lactams, mercurials, oxymercurials, azoles, oxazoles, thiazoles, pyrazoles, purines, pyrimidines, etc. have been synthesized under microwave irradiations coupled with inorganic solid supports. The compounds thus synthesized have shown moderate to excellent antimicrobial activities.

A.D. Mishra, PhD*

*A.D. Mishra is a Professor of Chemistry in the Department of Chemistry at Prithvi Narayan Campus, Pokhara. He has more than two decades of working experience in academia as a science educator and a researcher in various capacities. He has PhD degree in Chemistry from Delhi University, India. His research area is in synthetic and organic chemistry. He has authored more than 70 original research and general articles in his field of interest in various national and international journals. He is the author of five chemistry textbooks and two reference books. He has served as a chief executive editor of four research journals. He is also a recipient of Third World Academy of Science (TWAS) award.

Date: 01 April, 2017 19 Chaitra, 2073

EPISODE - 03

Biomimetic Potentiometric Sensor For Chlorgenic Acid Based On Electrosynthesized Polypyrrole

Abstract

A sensor was fabricated by modifying pencil graphite electrodes with molecularly imprinted polypyrrole (MIPpy) synthesised by electropolymerization of pyrrole monomer at constant potential in the presence of chlorogenic acid (CGA). A comparison between the non-imprinted modified pencil graphite electrode and the molecularly imprinted pencil graphite electrode is reported. Several important parameters controlling the performance of the polypyrrole and the method efficiencies were investigated and optimized. Surface morphology of imprinted and non-imprinted sensor was characterized by scanning electron microscope (SEM) and atomic force microscope (AFM). The molecularly imprinted layer exhibited selectivity and sensitivity toward CGA. Under optimized conditions, the calibration curve demonstrated linearity over a concentration range of 1 x 10-2 mol/L to 1 x 10-6 mol/L with a correlation coefficient (R2) of 0.993 and has life span of more than 3 months without any considerable change in the measured response. The sensor exhibited a sensitivity of -54.7 mV per decade. As an application, this potentiometric sensor has been successfully applied to the determination of CGA content in four different coffee samples and compared with HPLC results.

Kisan Koirala*, PhD

*Kisan Koirala is the CEO of Public Educational and Research Institute, Pokhara. He has PhD degree in Chemistry from University of Brunei Darussalam, Brunei. His research area is in materials and sensors system for technologies of various interests which by its theoretical and practical implications, is of multidisciplinary nature. He has several original research articles published in international conference proceedings and peer-reviewed journals. He has experience of working as a researcher in South Korea, Spain, Sweden and Brunei.

Abstract

Photovoltaic, literary means conversion of photon to voltage, technology is the promising technology to address the future energy demand in the world. Increasing efficiency and reducing cost are the major issues in this field. In this study, focus is done in the introduction of PV solar cells, its current status and numerical simulation of perovskite-based solar cells to enhance the performance and reduce the cost. The simulation of the solar cells at four sites of Nepal is carried out and found almost similar efficiency. But, Jumla is the place where solar cell performs better than the other places.

Krishna Raj Adhikhari*, PhD

*Krishna Raj Adhikari is a PhD scholar at Tribhuvan University. He is Associate Professor of Physics in Pashchimanchal Campus, IOE/TU, Pokhara. He has more than two decades of working experience in academia in various capacities. His
research interest and expertise includes, but not limited to, clean energy, physics and society, physics education etc. He had been a visiting scholar at Polytechnic University of Valencia, Spain. He has authored several peer-reviewed journal articles as well as popular articles in physics and other societal issues. His
academic leadership as a physics
educator and researcher is well established around and beyond Pokhara.

Date: 04 March, 2017 21 Falgun, 2073

INCEPTION

Science: State of Mind

Abstract

Science has changed the physical world around us so much that no one can, even remotely ignore its importance. Every human endeavor, even age-old cultural and religious practices have to clain being scientific to remain relevant in modern times. The achievement of science and the effects of science in society have been topics of much of public intellectual discourse. With the progress of instrumental aspects of science, it is often assumed that the society also progresses towards more rational and scientific modes of thinking and dealing its affairs. This assumption is far from being true around the globe, particularly in Nepal and the countries alike. The talk will try to address this particular issue and focus on the importance of scientific temper for healthy and sustainable growth of science and research culture in a society.

Kapil Adhikari*, PhD

*Kapil Adhikari is a freelance physicist currently based in Pokhara. He has completed PhD in computational condensed matter physics from the University of Texas at Arlingtion, USA. He has over four years of experience as a postdoctoral researcher, lecturer and visiting scientist in various institutes in the USA and in Qatar Foundation in Qatar. He has authored more than 15 articles in internatinal peer reviewed journals. He is also member of newly formed Physics Research Initiatives(PRI) Pokhara.